Flexible liquid container

ABSTRACT

A flexible container ( 1 ) for holding a liquid including two walls ( 10, 11 ) made of a flexible material, the free overlaying edges of said walls being assembled together by a weld or an adhesive seam ( 12 ), so as to define an inner sealed volume of said container, the two said walls also defining a spout ( 13 ) designed to protrude outwards from a peripheral portion of the container, and an outflow channel ( 130 ) connecting said spout with said inner volume of said container, characterized in that one or several obstacles ( 14, 14 ′) formed by welding or bonding together the two walls is or are located in said inner volume substantially opposite and in the vicinity of the channel ( 130 ) leading to the spout ( 13 ) in such a manner as to limit the section of the passage available for the liquid between the inner volume and the outflow channel, while leaving open at least one narrowed passage ( 140, 141, 146 ) and in such a manner that a portion of the surface including the spout is deflected, this portion of the surface being substantially defined by the obstacle or the obstacles and by folds directed substantially transversally ( 142, 143 ) with respect to said obstacles.

The present invention relates to a flexible container for a liquid,provided with a self-sealing pouring spout.

Flexible containers for holding a beverage or some other liquid offerseveral advantages over rigid containers and, more particularly: theirlow cost of manufacture, the use of a minimal amount of material and asmall bulk after use. However, once opened and if no rigid pouring spoutis provided, either separate or welded/bonded to the flexible sheets ofthe container, they cannot be easily closed once opened and they tend toallow the liquid to escape. Once the container is opened, the user musthold the container to prevent the liquid from being involuntarilyspilled and he cannot leave it to stand on a table or on some othersurface, unless it is completely empty.

Various flexible containers with a self-sealing spout have beensuggested for overcoming this problem. Generally, either an increase inthe resistance to the flow of the liquid is suggested by providing thecontainers with long thin channels in fluid communication with the spoutdeveloping a high resistance to flow, as described in the GB patent 769810 and the U.S. Pat. No. 4,988,016, or a narrowing or some otherobstacle in the vicinity of the spout developing a strong resistance tothe flow of the liquid, such as described in the U.S. Pat. No.5,411,178.

In the U.S. Pat. No. 4,988,016 and in the GB patent 769 810, theself-sealing effect depends mainly on the elasticity characteristics ofthe material of which the container is made, on the dimensions of thespout as well as on the characteristics of the liquid. In those systemswhich rely on a strong local resistance, such as those described in theU.S. Pat. No. 5,411,178, the self-sealing effect is strongly dependantupon the dimensions of the passage as well as on the characteristics ofthe liquid and in particular on its surface tension. In all the priorsolutions, the self-sealing effect is strongly dependent on thecharacteristics of the liquid and/or on the properties of the materialof the flexible container and a given spout geometry can often be usedonly for a specific liquid, owing to the fact that the self-sealingeffect is affected by variations in the dimensions of the channel or ofthe restriction. Another important disadvantage of these systems isthat, in order to achieve a reliable self-sealing effect, it isnecessary to have a high resistance in the outflow channel which limitsstrongly the flow rate and necessitates that a considerable compressiveforce be applied by the user to empty the container. Furthermore, aftera first use of the container, the self-sealing effect tends to subside,which results in involuntary leaks.

The same holds true for the container described in the patentapplication WO 98/01361 which discloses the use of spouts which areshaped differently depending on the liquid held in the container.

Other known sealing means rely on the formation of folds after use bythe user, such as described in the U.S. Pat. Nos. 3,278,085, 5,228,782and 6,244,468. These solutions have the drawback of not providing aself-sealing effect and of requiring an intervention by the user.

Accordingly, an objective of the invention is to provide a flexiblecontainer for a liquid, with a self-sealing spout, which is improved bycomparison with those already known.

Preferably, the self-sealing effect depends only little on theproperties of the liquid held in the container, it is reliable and itallows an outflow without requiring an excessive pressure by the user.

Preferably, the pouring spout of the container has a form, which issimple and easily manufactured, using a minimal amount of material andat a minimal cost.

In order to achieve the objectives of the invention, a flexiblecontainer is provided, which has the characteristic features set out inclaim 1. Specific embodiments are described in the dependant claims.

A specific embodiment is described hereafter, with reference to theappended drawing, including figures, in which:

FIG. 1 is a top view of the container according to the invention;

FIG. 2 is a front view of the container of the previous figure placed ona flat surface;

FIG. 3 is a side view of the same container placed on a flat surface;

FIG. 4 is a top view of a container according to a second embodiment ofthe invention; and

FIG. 5 is a perspective view of the second embodiment.

FIG. 6 is a top view of a container according to another embodiment ofthe invention; and

FIG. 7 is a perspective view of the container according to FIG. 6.

The container 1 illustrated in the figures is made from two sheets 10,11 of a flexible material, which have the same shape and the samedimensions, and which are fixed together by a weld seam or an adhesiveseam 12 running along the periphery of the container 1. In addition torunning along the periphery of the container proper, the assemblage seamprovided as a weld seam 12 also surrounds a spout 13, protruding from aportion of the periphery of the container. Thus, the spout 13 is madefrom the same sheets of flexible material as those forming the container1 and it includes an outflow channel 130 opening inside the flexiblecontainer 1. Furthermore, the spout 13 can include a weakening groove131, which makes it possible to tear off a portion thereof, thus openingthe spout 13 and the channel 130.

Inside the flexible container 1, in the vicinity of the location wherethe channel 130 opens inside the flexible container, the two flexiblesheets 10 and 11, made from a polymer or from some other flexiblematerial, are welded or bonded together in such a manner as to form anobstacle 14 located facing the outflow channel. The welded obstacle 14has an elongated shape and extends between two ends 15 which overlap theperipheral weld 12 on both sides of the outflow channel, while leavingfree two passages 140, 141 in the direction of the channel 130. Thelength L of the overlap is relatively small, compared with the overalllength of the peripheral weld 12 and it corresponds, preferably, to lessthan 10% thereof. Preferably, the longitudinal obstacle runssubstantially parallel to the portions of the peripheral weld 12 on thetwo sides of the outflow channel and approximately perpendicularly tothe general direction of the protruding spout.

When the container 1 is filled via a filling spout (not illustrated) andsealed permanently after the filling, the large central parts of the twowalls 10 and 11 forming the container 1 move away from each other as thecontainer swells, as can be seen in FIGS. 2 and 3.

When the container 1 is filled and the walls 10 and 11 are, accordingly,pushed away from each other, two folds are formed on each one of thewalls 10 and 11, extending transversally with respect to the narrowedpassages 140 and 141, approximately along the axes 142 and 143 shown inFIG. 1. The deformation of the walls 10 and 11 in the vicinity of theends of the obstacle 14—namely of two portions of each wall 10 and 11,which adjoin the two sides of the narrowed passages 140 and 141 andwhich are prevented from moving away from each other—creates a foldapproximately along the axes 142 and 143.

The folds 142, 143, as well as the generally elongated obstacle 15,define along approximately the dotted nip line 144, shown in FIG. 1,with the section 12 a of the seam extending between the fold lines 142,143 a portion of the surface, which tends to curve (deflect) asillustrated in FIGS. 2 and 3. The deflection of the area 145 includingthe spout, between the folds 142, 143, results in the two flexiblesheets in this area being urged against each other and thus forming avalve which prevents the flow of liquid through the passages 140, 141and via the orifice of the protruding spout 130.

When the flexible container is laid on a flat surface as illustrated inFIGS. 2 and 3 and a vertical force F_(v) is applied approximately on thelarge central part of the upper wall 10, the folds 142, 143 and thedeflection of the central deflection area 145 tend to reinforce, thusincreasing the tightness of the valve.

This reinforcement of the folds 142, 143 in the vicinity of the passages140, 141, as well as the increase in the deflection of the area 143which increases with the application of a force Fv which issubstantially perpendicular to the plane of the flexible sheets areextremely advantageous, since they prevent effectively the escape ofliquid when the flexible container is laid in its natural position on asurface which is substantially flat, even when another object, whichincreases the pressure in the container, is placed on top of thecontainer.

It is to be noted, that the deflection of the area 145 is nonsymmetrical, since the area 145 is deflected on one side or on the otherside of the container. The deflection is a consequence of the particulargeometry of the obstacle 15 which is either welded or bonded, and of itsposition with respect to the protruding spout portion 130 and the seamportion 12 a, which, together, determine the formation of the folds 142,143. In particular, the folds 142 and 143, as well as the obstacle 15,define a nip line 144 between the two flexible sheets. This line is notstraight, but has a generally curved shape of which the ends cut acrossthe peripheral seam. This nip line about the protruding spout, which isnot straight, makes it possible to cause the deflection of the spoutarea 145.

In order to enable the liquid to flow via the spout 13, the user simplyneeds to exert a certain pressure on the container, in particular bypressing the container at least partly along a direction F_(h), which issubstantially perpendicular to the plane of the weld of the obstacle 14,thus opening the lips closing the narrowed passage or passages 140, 141.The interruption of this compressive action closes the narrowed passagesand closes the container.

The exertion of a compressive force on the container in the directionF_(H), i. e. substantially perpendicularly to the plane of the weld ofthe obstacle results in a decrease of the deflection and of the effectof the folds 142, 143, accompanied by an increased pressure of theliquid in the container which opens slightly the lips of the sheets atthe entrance to the passages 141, 140, to enable an outflow of theliquid. In fact, when a compressive force F_(H) is applied approximatelyon the lateral sections 12 b of the seam, which is accompanied by anincrease of the pressure inside the container, a pulling force F_(T) anda torque F_(R) act on the portion of the seam in the vicinity of thespout which tends to flatten, i. e. to reduce the deflection of thespout area 145.

Owing to the fact that the narrowed passages 140, 141 have a lengthwhich is very small and a geometry which is very simple, theeffectiveness of the sealing does not depend as strongly on theproperties of the liquid and the elasticity of the material of thepackaging as in known flexible containers. Furthermore, considering thatthe protruding spout 13 is not required to have a particular shape, thesame can be very compact and simple, for example be straight as in theexample illustrated in the figures, which facilitates its manufactureand its use and reduces the amount of material needed. Another advantageis that the shape of the weld for creating the obstacle is very simpleand, accordingly, it can be formed rapidly and at a low cost onindustrial machines used for making packaging items, in the sameoperation as that carried out for forming the peripheral weld seam.

Also, a given flexible packaging can contain any type of liquid, theonly limitation being the chemical compatibility of the liquid with thematerial forming the container.

The figures show a container 1 having a substantially circular shape; itis however understood, that this container can assume any shape adaptedto its use. In the case of a container of a design having one side witha straight edge, the container can be formed from a single sheet of aflexible material folded over along this straight edge, with theremaining edges being welded together to form the container. Forexample, and as shown in FIGS. 6 and 7, a container according to theinvention is shown wherein the walls 10′, 11′ of the container are madefrom a single sheet of flexible material which is folded (along 12′) toform two overlying walls 10′, 11′.

Furthermore, the embodiment of the flexible container illustrated anddescribed has an obstacle 14 defining two narrowed passages 140 and 141.One could also have one end of the obstacle 14 in contact with theneighbouring portion of the weld 12, thus leaving only one narrowedpassage, with a single fold being then formed on the walls 10 and 11upon the filling of the container.

In another embodiment, such as that illustrated in FIGS. 4 and 5, thecontainer has a shape, which is substantially rectangular, and the spout13 is positioned in a corner of the rectangle to protrude in a directionalong an oblique axis approximately along the median line between theedges of the adjoining rectangle. In this embodiment, a welded obstacle14′ is arranged facing the spout as in the previous embodiments, exceptthat this obstacle is provided with a central passage 146. In thisembodiment, the deflection of the spout area 145 defined by the nip line144 is substantially the same as in the case of the embodiment describedpreviously. However, because of the rectangular shape of the containerand of the position of the spout in a corner thereof, a compressiveforce applied by the user to the central part of opposite edges 12 b ofthe container creates a pulling force and a torque which are lesspronounced on the spout area 145 by comparison with the embodimentdescribed previously. However, owing to the rectangular shape of thecontainer and of the position of the spout in one corner thereof, acompressive force exerted by the user upon the central part of theopposite edges 12 b of the container generates a pulling force and atorque which are less pronounced on the spout area 145 than in theembodiment described previously.

In the case of such elongated shapes in which the compressive force isexerted on the container at a relatively long distance from the spoutand where the spout is in a non symmetrical position of the containerwith respect to the compressive forces applied to the container, thecentral passage 146 provided in the welded obstacle makes it possible toinitiate and facilitate the flow of liquid in the passage of the spout.

1. A flexible container for containing a liquid, including twooverlaying walls of flexible material welded or bonded along aperipheral seam so as to define an inner sealed volume, said containercomprising an outwardly protruding spout and an outflow channelconnecting said spout with said inner sealed volume of said container,wherein one or several obstacles formed by welding or bonding together aportion of said two overlaying walls is or are located in said innersealed volume substantially opposite and in the vicinity of the outflowchannel thereby leaving open at least one restricted passage between theinner sealed volume and the outflow channel, the position of the one orseveral obstacles relative to the spout and the peripheral seam beingsuch that a portion of the overlying walls including the spout andbounded by the obstacle or the obstacles and by folds directedsubstantially transversally with respect to said obstacles deflects orarches when liquid is present in the inner sealed volume, and whereinthe obstacle has an elongated shape and extends between two endsoverlapping the peripheral seam on either side of the spout by an amountthat is less than 5% of the overall length of the peripheral seam.
 2. Aflexible container according to claim 1, wherein the obstacle definestwo said restricted passages at two opposite sides of the outflowchannel of the spout.
 3. A flexible container according to claim 1,wherein the spout has a generally straight shape and extendssubstantially perpendicularly to a peripheral portion of the containerto which it is affixed.
 4. A flexible container according to claim 1,wherein the spout includes a groove for tearing off a portion of thespout.
 5. A flexible container according to claim 1, wherein the wallsof the container are made from a single sheet of flexible material,which is folded over to overlay said two walls.
 6. A flexible containeraccording to claim 1, wherein the walls of the container are made fromtwo separate sheets of flexible material.
 7. A flexible containeraccording to claim 1, wherein the obstacle extends substantiallyparallel to portions of the peripheral seam located on either side ofthe spout.
 8. A flexible container according to claim 1, comprising atleast two said obstacles spaced apart by a narrow passage facing theoutflow channel of the spout.